Which PowerBook do I need to buy?

Hey guys,
I am about to start shooting a 10 minute short in about a week. In order to offload P2 cards, I am going to buy a laptop. Because I am an Apple guy (of recent) and use FCP I really want to get a mac laptop. I can't afford the new MacBook Pro with the P2 reader, and actually there is really no need for me to get the Intel Based MacBook Pro since I would have to buy an adapter for the P2 cards, so by default I am going to get a Powerbook. Now, as I understand it there are 12inch, 15inch, and 17inch models. I think the 12inch is called an IBook perhaps, and then the 15 and 17 are called PowerBooks. So, my question is... do all of these have the PCMCIA slot that I need for offloading?
Secondly, when I go to look at one (because I will be buying used of course) is there a way to make sure the slot is working. If I bring a P2 card with me, can I just put it in the slot and know that it is working or will software need to be on the computer first?
thanks guys for all the help
jare

The 15" PowerBook does have the slot. I think Noah is recommending the 17" because of the screen real estate and the bump in speed. It really is a better investment and shouldn't cost much more. Avoid the iBooks and MacBooks as they do not have the slot.